Anchors used to secure sutures, tissue grafts, or other components are ideally as small as possible while providing sufficient strength for their designed task. Smaller size may be advantageous to one or both decrease surgical trauma and to enable implantation in smaller anatomical structures. In some circumstances, such as but not limited to when an anchor is used in a knotless anchoring system where no guide instrument is provided, high stresses may be created in an anchor during implantation. Impacting, positioning, or repositioning of anchors may also create high stresses in an anchor. A specific non-limiting example of creating relatively high stresses in an anchor is when the anchor is used as a pivot point to lever a humeral head to gain an effective trajectory for implantation. In such a circumstance, an anchor that would be strong enough to meet load requirements of the anchor in a completed construct may not be of adequate strength to withstand the loads generated when being used as a pivot point. One way of addressing the need for a stronger anchor during implantation is to just use a larger diameter anchor. However, use of a larger diameter anchor may create additional surgical trauma and may not fit a patient's available anatomic implantation site in some circumstances.
It would be advantageous to provide an anchor that is of a relatively small size that may be strengthened or reinforced during implantation. Particular instrumentation and methods may also be required to implant such an anchor. It may be further advantageous to provide a portion of an implantation instrument that is capable of both strengthening or reinforcing an anchor and selectively engaging and disengaging suture or tissue that the anchor is used to attach.